Gas indicating apparatus



June 7, 1932. B, TREBlTscH 1,861,989

GAS INDICATING APPARATUS OrginalFiled April 2l, 1928 Patented June 7,1932 UNITED STATES PATENT GFFICE BRUNO TREBITSCH, OF VIENNA, AUSTRIA GASINDICATING APPARATUS Application led April 21, 1928, Serial No. 271,745,and in Austria January 19, 1928.

Renewed April 21, 15132.

My invention relates to an apparatus, which indicates the presence ofcombustible, explosive or poisonous gases in the air of a room where theapparatus is located and which is operated under the influence of gasesof greater as well as of smaller density than the surrounding air.

The object of the present invention is to perform the indication ofgases admiXed to the air by a reliable apparatus avoiding the drawbacksconnected with apparatus of known types and the operation of which isbased on the difference in the velocity of diffusion of air and gas andwhich operates independently of the density of the gas.

The apparatus according to this invention differs from the known typesin that the diffusion takes place subsequently from the outer air into aporous vessel enclosing another porous vessel and then from theintermediate space between these two vessels into the inner porousvessel. As the diffusion of gases always takes place from both sides ofthe porous wall, a pressure rise is prevented temporarily within thevessels, until the gases within the same are of the same density, i. e.of the same quality as the surrounding atmosphere. By the use of asecond porous vessel, the pressure rise within the inner vesf' sel willbe much greater than it would be where a single porous vessel is used.The pressure rise within the inner vessel serves to operate anelectrically or mechanically actuated signalling device in a well knownmanner.

The apparatus is shown in the accompanying drawing, wherein Fig. 1 is anelevation of the apparatus partly in a longitudinal section, whereasFig. 2 is a section of the casing with the apparatus in a side view.

According to Figs. 1 and 2, a vessel is tted with a diaphragm 1,preferably a diaphragm of a suitable size and shape e. g. a cylinder ofporous material, such as clay or the like, which is mounted by means ofsurrounding straps 2, 3 on a base plate 4 preferably made of wood, bymeans of two interposed pieces 5 of a soft elastic material, e. g. cork.The straps are tightened by means of screws and nuts 7, 8. The diaphragmin the shape of a cylindrical vessel'is closed on all sides and containsanother porous vessel or diaphragm 25, having one circular base incommon with the former, and at this circular base a tube 9, preferablymade of glass, is inserted and secured, so that no leakage is permittedat the joint. Preferably, the part of the Wall adjacent to the tube isof a tight material and made impermeable by varnishing. The glass tubeis partly filled with mercury 10, and two contact pieces or wires 11,12, preferably made of platinum, are cast in the wall of the tube andare connected by wires 13, 14 with the terminals 15, 16 at the casing17, the bottom of which remains open, or at the base plate el. Adjustingscrews 18 and 19 are arranged at the latter to adjust its position insuch a way that the level of a quantity of current conducting liquid, e.g. mercury, within the tube is at a small distance from the uppercontact piece 11.

rlhe terminals 15, 18 are connected to a source of electromotive force,e. g. a battery 20 and to avoid sparking effect when the current isslowly opened or closed, the conducting liquid within the tube iscovered with an insulating liquid, e. g. oil, petrol or the like, toprevent the conducting liquid at its surface from being oxydated. A bell21, or an indicating lamp, is connected in series with the battery. Y

If the atmosphere of the room, where the apparatus is located isidentical with that of the gas enclosed within the diaphragm, thepressure of the latter is identical with that of the atmosphere, and theconducting liquid remains at rest in the tube 9. If, however, even asmall quantity of gas, which i-s not present within the diaphragm isadmiXed `to the atmosphere of the room, the gas is diffusing into thediaphragm and the internal pressure is increased, whereby the conductingliquid is displaced within the tube and the circuit closed between thecontacts 11 and 12.

A signalling device, a bell or the like, may also be connected in acircuit so that the circuit closed by the mercury acts upon a relay,which causes the bell to ring continuously even after the gas has ceasedto influence the diaphragm and the mercury has returned to its previousposition and the current in the tube has been interrupted.

What I claim is 1. An apparatus for indicating the presence ofcombustible, explosive or poisonous gases, comprising a porous vesselhaving double porous Walls, and a pressure indicating means connectedWith lsaid vessel so as to indicate the pressure Within the inner porousWall.

2. An apparatus for indicating the presence of combustible, explosive orpoisonous gases, comprising a porous vessel having double porous Walls,and a U-shaped tube partly filled with mercury and constituting apressure indicating means operatively connected with said vessel, oneterminal of said tube being permanently covered by the mercury and theother terminal located With its end at a small distance above the levelof the mercury.

3. An apparatus for indicating the presence of combustible, explosive orpoisonous gases, comprising a porous vessel having double porous Walls,a U-shaped tube partly filled with mercury and constituting a pressureindicating means operatively connected with said vessel, a terminallocated above the level of the mercury, and means for adjusting theapparatus so as to bring the mercury level as near as possible to saidterminal Without touching the same.

4. An apparatus for indicating the presence of combustible, explosive orpoisonous gases, comprising a porous vessel having double porous Walls,and a pressure indicating means adapted to indicate the pressure withinthe inn-er porous Wall, both porous walls having a common impermeablebase plate thereby preventing direct communication from the inner porousWall to the outer In testimony whereof I have hereunto set my hand.

ING. CHEM. BRUNO TREBITSCH.

